Suicidal ideation (SI) and suicide attempts (SA) continue to be a serious concern among older adults, with depression affecting an estimated 7% of all adults over age 65 years (11) and the highest worldwide suicide rates documented for older men.(3,7) Suicide prevention for older adults has unique challenges because older suicidal individuals are more likely to use advance planning and less likely to ask for help.(9) Prior work has suggested that clinicians may under-diagnose or under-treat depression and SI among older adults.(21-22) Early recognition and treatment of depression, as well as improved management of chronic health conditions, can make a difference among older adults by improving quality of life and reducing morbidity and mortality.(25) There is evidence that targeted interventions in primary care settings can improve rates of screening and treatment for depression (41), but very little is known about SI/SA among older emergency department (ED) patients, who may be at increased risk compared to the general population because of comorbidities (32) and acute physical (32) or psychosocial (33) stresses. While some EDs are moving towards universal screening for SI/SA, most still rely on targeted questioning triggered by clinician concern. Understanding which older ED patients may be suicidal could help clinicians more easily identify this high-risk group, and understanding current patterns of treatment-including identification of disparities in care between older and younger patients with SI/SA-could help improve ED care. The overall goal of this research is to lay the groundwork for the development of effective ED-based interventions for suicide prevention by better describing the population of older ED patients with self-harm/SI/SA. For our first specific aim, we use the large database from a multi-site trial of universal ED screening for SI/SA (Emergency Department Safety Assessment and Follow-up Evaluation, ED-SAFE) to provide an estimate of the prevalence of SI/SA among older ED patients, including variations among age groups. For our second specific aim, we will conduct a more detailed retrospective chart review at one ED to describe the patient characteristics and ED treatment of older ED patients with SI/SA, including possible disparities in care. The findings from this research proposal will provide the essential scientific foundation for future design and implementation of evidence-based interventions to improve ED recognition and care of older adults with suicidal thoughts or behaviors. Such interventions have the potential to improve the quality of life of older adults with mental illness and to prevent premature death from suicide.